The basic goals of this proposed research are to develop a new, general approach to the synthesis of prostaglandins and prostaglandin analogs, and to develop other synthetic methods that will be of broad interest to investigators involved in prostaglandin synthesis. Several new contributions in this latter area involve new approaches to the problem of incorporating the C13-C20 carbon moiety of the prostanoid skeleton on to activated cyclopentene derivatives. Progress to date has led to the development of a general synthesis of optically active cyclopentene diols which will be converted to the naturally occurring prostaglandin derivatives. BIBLIOGRAPHIC REFERENCES: A General Synthesis of 1-Alkyl-1-cyclopentene-cis-3,5-diols. Useful Intermediates in Prostaglandin Synthesis, D.A. Evans, T.C. Crawford, T.T. Fujimoto and R.C. Thomas, J. Org. Chem., 39, 3176 (1974). Methylthiotrimethylsilane: A Versatile Reagent for Thioketalization Under Neutral Conditions, D.A. Evans, K.G. Grimm and L.K. Truesdale, J. Amer. Chem. Soc., 97, 3229 (1975).